The invention relates to a filtration apparatus comprising in a housing an annular filtration chamber into which there is admitted a suspension under pressure and which is formed between an external filtration surface in the form of a body of revolution and an internal filtration surface which is nested therein and is also in the form of a body of revolution, the annular filtration chamber comprising at one of its ends a suspension inlet and at its other end an outlet for the product, and the filtration surfaces which are in the form of bodies of revolution are connected in each case to a filtrate discharge collector.
In filtration apparatus of this kind, the suspension under pressure which is to be processed is conducted by way of a suspension inlet into an annular filtration chamber. The liquid which is to be separated out passes through the filtration surfaces which are in the form of bodies of revolution and is taken away as a filtrate by means of a filtrate discharge collector connected with each of the filtration surfaces. The product which remains in the filtration chamber moves through the filtration chamber in the direction towards a product outlet, through which the product issues from the filtration apparatus. Thus the filtration apparatus operates continuously with a continual throughflow of suspension or product respectively between the filtration surfaces which form the filtration chamber.
But in the case of many suspensions which are processed a solid cake layer forms on the filtration surfaces and the known filtration apparatus is then not suitable for filtering a suspension of that kind.